Income Per Share - Schedule of Computation of Diluted Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	May 26, 2018	May 27, 2017	May 26, 2018	May 27, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 36,359	$ 24,362	$ 128,943	$ 75,092
As reported - Basic (in shares)	19,533	20,308	20,036	20,290
Add: Undistributed earnings allocated to unvested participating shares		$ 166		$ 523
Less: Undistributed earnings reallocated to unvested participating shares		(157)		(496)
As reported – Diluted	$ 36,359	$ 24,199	$ 128,943	$ 74,581
As reported - Diluted (in shares)	19,687	20,279	20,178	20,254
As reported - Diluted (in dollars per share)	$ 1.85	$ 1.19	$ 6.39	$ 3.68
Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 30,034	$ 19,307	$ 104,324	$ 59,486
As reported - Basic (in shares)	15,446	15,326	15,463	15,305
As reported - Basic (in dollars per share)	$ 1.94	$ 1.26	$ 6.75	$ 3.89
Add: effect of dilutive potential common shares	$ 0	$ 0	$ 0	$ 0
Add: effect of dilutive potential common shares (in shares)	154	107	142	103
Class B Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 6,325	$ 4,883	$ 24,619	$ 15,068
As reported - Basic (in shares)	4,087	4,846	4,573	4,846
As reported - Basic (in dollars per share)	$ 1.55	$ 1.01	$ 5.38	$ 3.11
Add: effect of dilutive potential common shares	$ 6,325	$ 4,883	$ 24,619	$ 15,068
Add: effect of dilutive potential common shares (in shares)	4,087	4,846	4,573	4,846